Here is a generalized ppm guide for different plant stages (some will require more, some less):
Seedlings: 100-250 (nutrients aren’t needed here, hence there’s not a lot of particles needed)
First Half of Vegging Cycle: 300-400 (this is usually after you transplant, which still doesn’t require many nutrients)
Second Half of Vegging: 450-700 (you’ll start giving your plants more nutrients at this stage)
First Half of Flowering: 750-950 (your plants will be eating more as they grow, so they’ll be taking in more nutrients)
Second Half of Flowering: 1000-1600 (this is when your plant’s eating the most, especially if you give it additives)
End of Flower, Entering Harvest: As close to 0 as possible (this is when you’ll be flushing your plants, so you don’t want there to be a lot of particles leftover)
When reading runoff to determine what the plant is consuming, you want the runoff to be close to what you put in.
Example: you test your nutrient solution before giving it to the plant. Ppm reads 1200. You water the plant until you get around 10-20% of the water coming out of the pot. Test that solution. If you’re near 1200ppm, you’re at a good level of ppm for the plant. If you’re getting 1700ppm reading in the runoff, you can back off on the amount of nutrients because the plant isn’t able to consume everything you’re giving it. On the other hand, if you’re getting 800ppm in the runoff, you can bump up the amount of nutrients on the next feed because she’s not getting enough.
Being off 100 or 200 PPM isn’t usually a big deal. It is far better to underfeed than it is to overfeed. Your plants will tell you when there is a problem and we can help you with that. An underfeeding situation can be resolved for the plant very easily and very quickly. It is not really the case with overfeeding, which will take more effort and more time to correct.
As you are in Happy Frog, you won’t need to fertilize at all until at least 4 weeks from your last transplant, regardless of what the feed schedules say. Your PPMs will be high enough for that period just based on what is in the bagged soil.